University of Luxembourg

About: University of Luxembourg is a education organization based out in Luxembourg, Luxembourg. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 4744 authors who have published 22175 publications receiving 381824 citations.

A process specification formalism

Abstract: Traditional methods for programming sequential machines are inadequate for specifying parallel systems Because debugging of parallel programs is hard, due to eg nondeterministic execution, verification of program correctness becomes an even more important issue The Algebra of Communicating Processes (ACP) is a format theory which emphasizes verification and can be applied to a large domain of problems ranging from electronic circuits to CAM architectures The manual verification of specifications of small size has already been achieved, but this cannot easily be extended to the verification of larger industrially relevant systems To deal with this problem we need computer tools to help with the specification, simulation, verification and implementation The first requirement for building such a set of tools is a specification language In this paper we introduce PSFd (Process Specification Formalism draft) which can be used to formally express processes in ACP In order to meet the modern requirements of software engineering, like reusability of software, PSFd supports the modular construction of specifications and parameterization of modules To be able to deal with the notion of data, ASF (Algebraic Specification Formalism) is embedded in our formalism As semantics for PSFd a combination of initial algebra semantics and operational semantics for concurrent processes is used A comparison with programming languages and other formal description techniques for the spedfication of concurrent systems is included

Combining static analysis with probabilistic models to enable market-scale Android inter-component analysis

Abstract: Static analysis has been successfully used in many areas, from verifying mission-critical software to malware detection. Unfortunately, static analysis often produces false positives, which require significant manual effort to resolve. In this paper, we show how to overlay a probabilistic model, trained using domain knowledge, on top of static analysis results, in order to triage static analysis results. We apply this idea to analyzing mobile applications. Android application components can communicate with each other, both within single applications and between different applications. Unfortunately, techniques to statically infer Inter-Component Communication (ICC) yield many potential inter-component and inter-application links, most of which are false positives. At large scales, scrutinizing all potential links is simply not feasible. We therefore overlay a probabilistic model of ICC on top of static analysis results. Since computing the inter-component links is a prerequisite to inter-component analysis, we introduce a formalism for inferring ICC links based on set constraints. We design an efficient algorithm for performing link resolution. We compute all potential links in a corpus of 11,267 applications in 30 minutes and triage them using our probabilistic approach. We find that over 95.1% of all 636 million potential links are associated with probability values below 0.01 and are thus likely unfeasible links. Thus, it is possible to consider only a small subset of all links without significant loss of information. This work is the first significant step in making static inter-application analysis more tractable, even at large scales.

StaDynA: Addressing the Problem of Dynamic Code Updates in the Security Analysis of Android Applications

Abstract: Static analysis of Android applications can be hindered by the presence of the popular dynamic code update techniques: dynamic class loading and reflection. Recent Android malware samples do actually use these mechanisms to conceal their malicious behavior from static analyzers. These techniques defuse even the most recent static analyzers that usually operate under the "closed world" assumption (the targets of reflective calls can be resolved at analysis time; only classes reachable from the class path at analysis time are used at runtime). Our proposed solution allows existing static analyzers to remove this assumption. This is achieved by combining static and dynamic analysis of applications in order to reveal the hidden/updated behavior and extend static analysis results with this information. This paper presents design, implementation and preliminary evaluation results of our solution called StaDynA.